The present invention relates to a transverse conveyance apparatus that is disposed in a roller conveyor line for transporting articles in a longitudinal direction, wherein the apparatus is designed to take the articles away from, or deliver them to, the roller conveyor line by transferring said articles transversely thereof.
Further, the present invention relates to a lift device capable of being incorporated in any apparatus that comprises such parts movable up and down as in the transverse conveyance apparatuses adapted to the roller conveyors.
Conveyor lines are used for transportation of articles in assembly lines for assembling products of various types and also in certain distributing stations. Generally, each conveyor line consists of a roller conveyor or a belt conveyor for moving the articles thereon longitudinally thereof. A plurality of such conveyor lines are usually arranged lengthwise and crosswise, instead of simply forming only one straight line. An article receiving/delivering apparatus is disposed at any desired point on each conveyor line. By operating the receiving/delivering apparatus, those articles having moved on one conveyor line will leave it to transfer onto another conveyor line. Sequence of such transferring and transporting operations will cause the articles to advance towards and arrive at a desired destination.
Transverse conveyance or feed apparatuses (sometimes called xe2x80x9ccross-feedersxe2x80x9d) that have been known as the article receiving/delivering apparatuses do each comprise unit belt conveyors as main parts respectively interposed between two adjacent rollers forming a roller conveyor line. The transverse conveyance apparatus of this type for moving the articles lying on the conveyor line will deflect them to advance transversely of the conveyor line, as disclosed for instance in Utility Model Laying-Open Gazette Hei. 5-3224 and Patent Laying-Open Gazette Hei. 6-312832.
The known cross-feeder consists of a crosswise feeding mechanism and a lifting mechanism. While the articles on a conveyor line are transported along a main lengthwise conveying line, the upper support plane of the crosswise feeding mechanism will be kept below that of the lengthwise conveying line. If and when the articles are to be taken sideways off the conveyor line or the latter is to be loaded with the articles, a stopper or any appropriate means will operate to hold those articles still above the cross-feeder. The lifting mechanism will then be activated to raise the upper support plane of cross-feeding mechanism above the upper surface of the lengthwise conveying line, to thereby lift the articles. Subsequently, the crosswise feeding mechanism will be turned on so as to transfer those articles onto another conveyor or to receive therefrom those articles.
The Gazette Hei. 6-312832 discloses a motor-installed roller as the drive source for the lifting mechanism that is built in the cross-feeder, wherein the roller comprises a cylindrical member enclosing a motor and a reducer.
FIG. 13 is a scheme of the cross-feeder disclosed in the Gazette Hei. 6-312832. This feeder 100 consists of a crosswise feeding mechanism 101 and a lifting mechanism 102, and a motor-installed roller 105 is utilized as the principal member of said mechanism. Rings 106 are attached to the outer peripheral zones of the motor-installed roller 105. A link 108 has its one end connected by a pin 107 to each ring 106, with the other end of the link being connected to the crosswise feeding mechanism 101.
With the pin 107 taking its uppermost position, the crosswise feeding mechanism 101 will have its upper face lifted above the conveying surface of the conveyor line as seen in FIG. 13. When the feeding mechanism 101 has to take refuge from the conveying surface of said line, the motor-installed roller 105 will be turned on to rotate a quarter of a circle so that the pin 107 is put down and said body 101 descends.
The cross-feeder disclosed in the Gazette Hei. 6-321832 has a compact overall size, because its lifting mechanism 102 employs the roller 105 having the motor installed therein.
However, such a prior art cross-feeder 100 is somewhat disadvantageous in that its crosswise feeding mechanism 101 will not necessarily be so stable in its position when raised by the lifting mechanism 102.
In detail, the reducer installed together with the motor in the roller 105 as mentioned above has backlash of a designed degree. Although such backlash causes no problem while the motor is rotating, the cylindrical casing of the roller will become shaky due to the backlash once the motor is inactivated. In general, the reducer accommodated in said roller is of such a structure as to make itself a reverse rotation within a certain angle. Thus, the crosswise feeding mechanism 101 raised in the prior art cross-feeder 100 is not so stable but considerably shaky.
Further, the motor-installed roller 105 in the prior art cross-feeder 100 must repeat to turn forwards and then backwards. This is because the rings 106 integral with the cylindrical casing of said roller are operatively connected by the pins 107 to the crosswise feeding mechanism 101. The lifting mechanism 102 illustrated in FIG. 13 has its links 108 possibly interfering with the roller""s 105 cylindrical casing, so that this motor-installed roller cannot rotate 360 degrees. Therefore, in the prior art cross-feeder 100, the roller 105 has to turn about a quarter of a circle in a forward direction to raise the feeding mechanism 101 and then to turn backwards also about a quarter of the circle to lower the crosswise feeding mechanism 101.
As a result, the reducer and other relevant parts in the motor-installed roller 105 tend to become abraded in part, thereby early causing troubles in operation.
In addition, the roller 105 is driven fore and aft an angle of only a quarter of circle in the prior art cross-feeder 100, so that a vertical stroke thus rendered relatively small has been felt unsatisfactory. Further, the rings 106 necessitated in building the prior art feeder has undesirably increased the number of constituent parts thereof.
An object of the present invention is thus to provide a transverse conveyance apparatus not only smaller in size and freer from troubles but also comprising a crosswise feeding mechanism that is much more stabilized in positions thereof. Another object is to provide a lift device designed effective to resolve problems similar to those which have been discussed above.
A transverse conveyance apparatus proposed herein for roller conveyors does comprise a frame, a crosswise feeding mechanism mounted to the frame and a lift device for raising and lowering the frame. The crosswise feeding mechanism has rotating portions, such as pulleys, rollers or conveying belts, so that articles are transported in a direction crossing that in which the articles are to advance on and along the roller conveyor. Each of the rotating portions is of a width freely movable through between two adjacent rollers of the conveyor.
The lift device comprises a cylinder, lids closing opposite ends of the cylinder, fixed shafts protruding outwards and longitudinally of the cylinder that is coaxial with said shafts capable of rotating relative to the lids, a motor built in and driving the cylinder to rotate around and relative to the fixed shafts, a reducer built in the cylinder so as to reduce the motor""s rotational speed transmitted thereto, and a resistance unit also built in the cylinder and increasing resistance against rotation of said cylinder.
In the apparatus of the invention, attachment-engaging portions are formed on the respective lids and disposed longitudinally of the cylinder to face outwards so that the attachment-engaging portions and the cylinder do rotate together in unison with each other, the attachment-engaging portions having axes arranged offset with respect to axes of the fixed shafts.
Also in the apparatus of the invention, the fixed shafts are held in position in and by one member selected from the group consisting of the crosswise feeding mechanism and an immovable part, with the attachment-engaging portions being not only connected to the other member selected from said group but also capable of rotating relative to said other member.
In the present invention, the transverse conveyance apparatus utilizes a part similar to the prior art motor-installed roller. Therefore, the apparatus is also compact in its outer configuration.
The lids in the transverse conveyance apparatus have the attachment-engaging portions that are designed to rotate in unison with the cylinder and may typically be located outside it. Those attachment-engaging portions are arranged to be eccentric with respect to the fixed shafts. Either the fixed shafts or the attachment-engaging portions are connected to the cross-wise feeding mechanism, and correspondingly, either the attachment-engaging portions or the fixed shafts are connected to the immovable part or base.
The apparatus of the present invention will thus operate in such a manner that the rotating cylinder causes the crosswise feeding mechanism to move up and down relative to the immovable part or base.
The resistance unit installed in the cylinder of the apparatus provided herein will exert resistance against rotation of said cylinder. Thus, the cylinder is not so easily forced to rotate as would render it shaky.
The lift device provided herein from another aspect does comprise a cylinder, lids closing opposite ends of the cylinder, fixed shafts protruding outwards and longitudinally of the cylinder that is coaxial with said shafts capable of rotating relative to said lids, a motor built in and driving the cylinder to rotate around and relative to the fixed shafts, a reducer built in the cylinder so as to reduce the motor""s rotational speed transmitted thereto, and a resistance unit also built in the cylinder and increasing resistance against rotation of said cylinder, wherein attachment-engaging portions are formed on the respective lids and disposed longitudinally of the cylinder to face outwards so that the attachment-engaging portions and the cylinder do rotate together in unison with each other, the attachment-engaging portions having axes arranged offset with respect to axes of the fixed shafts.
The lift device of this structure uses the resistance unit installed in the cylinder so that resistance will always be applied thereto, thereby rendering it less shaky against any unintentional external force. The number of parts or members required to construct the lift device will be decreased, since the attachment-engaging portions are formed on and integral with the lids.